Coal for use in home fireplaces and the like has gained increasing popularity in recent years. Of course, one drawback of a fuel of this sort is the excessive smoke it produces as it burns.
In the past, coal briquettes have been produced comprising coal dust or fines bonded by various binders, including sodium silicate. Such fines, however, are difficult to compact into briquettes and contain very little entrapped methane because of their high surface area, with the result that the burning qualities of such briquettes are not particularly good; and they are difficult to ignite.